A comparative study of compaction and CBR behaviour of stone dust reinforced with waste plastic strips

Abstract

The paper presents the comparative study of compaction and CBR behaviour of stone dust reinforced with LDPE and HDPE waste plastic strips. Two types of waste plastic strips (LDPE and HDPE) with three different lengths (12 mm, 24 mm and 36 mm) were used in this study. The comparison of the effect of strip content (0.1, 0.2, 0.4 and to 0.8 % by weight for LDPE strips and 0.25, 0.5, 1 and 2 % by weight for HDPE strips) on maximum dry unit weight and optimum moisture content was determined. The results of the study reveal that at all strip content and strip length, the stone dust specimens reinforced with LDPE and HDPE strips exhibited the similar compaction behaviour as the corresponding unreinforced stone dust specimen. Furthermore, there was a modest decrease in the maximum dry unit weight with the increase in the strip content of all lengths. However, the optimum moisture content was not affected by the increase in the strip content, strip length and strip type. The compaction results were used to study the CBR behaviour of LDPE and HDPE strip-reinforced stone dust. The test results indicated that addition of waste plastic LDPE strips in stone dust results in marginal increase in the CBR and the secant modulus whereas addition of waste plastic HDPE strips in stone dust resulted in an appreciable increase in the CBR and the secant modulus. The reinforcement benefit increased with an increase in LDPE and HDPE waste plastic strip content and strip length. Stone dust reinforced with HDPE strips is more effective than stone dust reinforced with LDPE strips in improving the behaviour of the system. The material can be used in base courses in constructing the rural roads there by leading to safe disposal of these waste materials in an environmental friendly manner.